Method of sweating out fusible metals



Feb. 5, 1935. w. F. EPPENSTEINER 1,989,352

METHOD OF SWEATING OUT FUSIBLE METALS Filed Aug. 4, 1933 INVENTOR ATI'ORNE S Patented Feb. 5, 11935 UNHTED STATES PATENT @FFEQE METHOD SVVEATING OUT FUSIBLIE METALS William F. Eppensteiner, Rahway, N. .l., assignor to The American Metal Company, Limited, New York, N. TL, a corporation of New York Application August 4, 1933, Serial No. 683,657

3 Claims. (Cl. 1 18-5) This invention relates to the separation of the any suitable pressure-say, for example, 150 more readily fusible metals from those of lesser pounds per square inch,--and in its flow through fusibility by the application of heat. An examthe superheater it may be raised to a temperature ple of such sweating treatment is the melting out suficient to impart the necessary heat for fusing 5 of solder from used automobile radiators. The out the solder or other fusible metal,say, for 5 method is applicable to various metallic strucexample, from 750 to 850 F. or 1000 F. The tures, the parts of which are united by solder, steam thus superheated is sprayed into the heater such as to the separation of lead coating from chamber, where it flows into contact with the electric wires, and in numerous other instances articles to be treated, its temperature being sufliwhere a more fusible metal or alloy is to be sepcient to melt out the more readily fusible metal 10 arated from a less fusible metal or alloy. The or alloy to be recovered, but insufficient to affect method commonly heretofore employed has been the other metal or metals of the objects under to place the material to be treated in an oven or treatment. The objects may be stirred or agitatretort and subject it to the heat of combustion ed in any suitable way for disengaging the solder applied either externally or internally thereof, or other fusible metal.

the more fusible metal or alloy falling into a The process may be practiced continuously by receiver or tray beneath, while the less fusible introducing the objects or matters to be treated metal or alloy is pushed out or otherwise removed at the inlet end of the chamber, causing them to from the container. move progressively through the chamber while According to the present invention the heating subjected to the action of the super-heated steam, 20

medium used is superheated steam, whereby a and finally ejecting them through the outlet end much higher recovery of fusible metal is obtained, of the chamber. The infeeding, progressive moveand the oxidation of the metals under treatment, ment, and outfeeding, of the objects or matters and the production of dross, are reduced to the to be treated and of the residual material may minimum. be accomplished by any means heretofore known 25 For illustration of the method, reference may be in heating chambers, ovens or furnaces of this made to the accompanying drawing, which illusgeneral type, and forms no part of the present trates diagrammatically a simple apparatus invention. Such means include any pushing, adapted for practising the method. feeding, conveying or agitating devices such as In the drawing, A designates a heating chamhave been heretofore employed for analogous 30 her having an inlet at B and an outlet at C. The purposes. inlet and outlet may be closed by doors D, D, The experience thus far had with this method or other closures, which may be opened to admit has resulted in the recovery of approximately the objects to be treated,one of which is desigtwice the proportion of solder recovered by the 5 noted at E,-and to discharge the treated obprocess using heat of combusticn within the heatjects or material from which the more fusible ing chamber. It has an important further admetal has been separated. F is a boiler, which vantage in diminishing oxidation. Tests heretomay be heated by a furnace G and from which fore made indicate that by the method comsteam is taken through a pipe H and carried in a monly heretofore employed it is impossible ensuperheating coil I through the furnace G, being tirely to exclude air, which is very chemically 40 introduced into the heating chamber through a active at the sweating temperature, especially nozzle J having perforationsfor the escape of the with tin and lead, with which its oxygen comsuperheated steam. bines to produce dross. The production of dross Assuming that automobile radiators or the like is further increased in many instances, as with are to be treated to melt out the solder, these rest automobile radiators, due to the extended area 4; within the chamber A on a grating K, through of solder seams or joints. By using superheated which the solder may drip into a trough or tray steam, air is excluded practically entirely and the L, from which at intervals it may be drawn off production of dross is reduced to the minimum.

' through a spout M by turning its gooseneck N With automobile radiators some air is inevitably down to the position shown in dotted lines, whereintroduced because of being contained in the cell- 50 by the solder is run into the collecting vessel 0. ular spaces or interstices of the radiator struc- The wastesteam may be discharged through pipe ture, but when the method is carefully practiced,

P, so that the steam pressure within the chamber that is practically the only air which is admitted is not high. to the chamber. By excluding air I also prevent In operation the steam may be generated at the oxidation of the higher melting point metals 55 Percent by volume i CO2- I which demonstrates how efiectively air is ex 15 cluded. V '1 The described'process is applicable not only for ;recovering solder from radiators, but also for melting'lead out of electrotype sheets and from lead-covered electric cables and other analogous 20 purposes, as well as for treating dross produced in the refining of solder and lead, and various other instances where a more highly fusible metal" or alloy or other substance is to be recovered from a metal or other material of lesser fusibility.

I claim as my invention:

1. The process of renioving vsolder or the like messes from automobile radiators or similar articles which consists in moving such article into and through a substantially closed chamber and without other material heating means fusing cut the solderf or the like from such articles by flooding the chamber with superheated steam in direct contact with the articles being treated, such steam o being "at low pressure, and excluding 2mm said f chamber any substantial quantities of air so that 5 the articles being treated are subjected only to the superheated steam during their transit through the chamber. 3

2. The process of claim 1 in which the superheated steam is introduced near the discharge end of the chamber, and passes through an exit pipe near the entrance of the chamber of sufficient diameter to prevent the building up of any considerable pressure in the chamber, but nevertheless creating suificient pressure to exclude the air during'the charging and dischargingmovements of the radiators.

3. The process of claim 1 in which the radiators or the like are subjected to agitation while the solder or the like is infused condition.

WILLIAM F. EPPENSTEINER. 

